I'm a freelancer constantly fighting with the lack of motivation (and problems like starting a project and never finishing it happen all the time). I'm looking for some app/website/technique which helps you getting motivated.
Maybe some kind of app that applies some technique, or which has some gamification...
Please don't recommend apps which give you motivational quotes as those doesn't work for me

If you haven't heard of the "Pomodoro technique" before, consider this your intro! It's an intensely helpful way to have a set amount of time to buckle down and work for that specified amount of time, and then once your timer goes off, you get break time, and the breaks are required! Helps keep you "fresh" and out of a rut.